1. Field of the Invention
The present invention relates to a technology concerning image processing, and particularly relates to image processing by way of a point image restoration process on the basis of a point spread function (PSF).
2. Description of the Related Art
Image deterioration caused by various aberrations of an optical system (e.g., imaging lens) sometimes occurs in an image obtained by capturing a subject by an image capture device such as a digital camera.
In order to prevent the image deterioration (diffraction blur, peripheral blur, chromatic aberration of magnification, etc.) caused by the aberration, a technology has been devised in which image data of the subject image is subjected to image processing to eliminate (correct) the image deterioration caused by the aberration.
The image deterioration due to the aberration may be represented by a point spread function (PSF), and the image deterioration may be eliminated by subjecting the image data to a restoration filter (inverse filter) of the point spread function (point image restoration process).
However, a false color or aliasing may be generated even more in some images by performing the point image restoration process, which reduces the quality of the image, in some cases.
Therefore, Japanese Patent Application Laid-Open No. 2010-086138 (hereinafter referred to as PTL 1) discloses a technology relating to an image restoration process (that may be considered to correspond to the point image restoration process of the present application) in which a portion where the false color is to be generated by performing the image restoration process is not subjected to the image restoration process. PTL 1 discloses it is preferable that the image restoration process is performed before a demosaicing process (that may be considered to correspond to a demosaicing process of the present application).
Japanese Patent Application Laid-Open No. 2011-124692 (hereinafter referred to as PTL 2) discloses that a restoration degree of the image restoration process may be continuously adjustable, and the false color generated can be suppressed by adjusting the restoration degree. However, the chromatic aberration of magnification is generated along with decrease of the restoration degree, which is disclosed also.